Worth remembering that airlines will often add all manner of notes/advisories/codes to a PNR. Some of these, where relevant, will then appear on a BP and/or manifest as used by the Purser and also ground staff.
For a few years I had a business-to-business relationship with American Airlines, and whenever they issued tickets for me, they would add (a useful!!) 'CIP' to my booking notes, and this would then appear on manifests etc, with the C standing for 'commercially' as opposed to 'very'
I have no idea whether a similar situation applies with the specific case you mention, but it's perfectly possible.